1. Field of the Invention
The present invention relates to a femtocell access point (FAP) device of a small cell, and more particularly, to a flexible connection control FAP device of a small cell which uses a maximum system load and maximizes network efficiency by calculating a system load occurring when a mobile station newly connects according to service types that the mobile stations, such as user equipments (UEs), in a small cell of a femtocell, etc., desire to use, comparing the calculated system load and a maximum system load, and determining and controlling whether to limit connection of the mobile station, and a method of driving the same.
2. Discussion of Related Art
A small cell is a base station which covers an area smaller than that of a mobile communication base station, and has a relatively low data process capacity compared to a macro base station. In an access point (AP) for the small cell, since the maximum number of users is set, phenomena of malfunctioning and decline in communication quality due to data service capacity excess of the AP are prevented. However, in conventional technology for limiting connection by limiting the maximum number of users, even when the number of connected users reaches the maximum number of users, data service capacity of an actual system does not reach the maximum number of users. For example, even if the number of connected users reaches the maximum number of users, when there are a plurality of voice over Long Term Evolution (VoLTE) users using only small amounts of data among the number of connected users, connection request of the mobile station is limited even when the data service capacity of the system is sufficiently empty. To improve the inefficiency, a method of flexibly controlling the maximum number of users based on the system load is needed.
As one example of background technology of the present invention, technology for authenticating mobile units attached in a femtocell communicating with a secure core network, such as an internet protocol multimedia subsystem (IMS), is disclosed in International Publication No. WO 2009/045317 as shown in FIG. 1. The technology relates to a method of communicating with the secure core network, such as the IMS network, and includes receiving a global challenge including information indicating a random number from a femtocell, and in a first secure entity of the IMS network, receiving an authentication response calculated by the mobile unit based on the random number and a first key announced by a mobile unit and not announced by the femtocell, and determining whether the random number is a legitimate number provided to the femtocell by the IMS network.
Other background technology of the present invention relates to a mobility management method for a third generation Long Term Evolution (LTE) system using a load dispersion-based adaptive handover shown in FIG. 2. The technology includes determining a load condition of a cell which is currently in service; when the load condition of the cell which is currently in service is an overload condition, calculating a handover hysteresis threshold of each of adjacent cells according to the handover hysteresis threshold of the cell which is currently in service and the load condition of the adjacent cells, for each of the adjacent cells of the cell which is currently in service; transmitting the calculated handover hysteresis threshold of each of the adjacent cells from the cell which is currently in service to user equipments (UEs) which are serviced; and performing a handover operation that a UE satisfying a condition that a difference between reception signal strength by at least one among the adjacent cells and the reception signal strength by the cell which is currently in service be larger than the handover hysteresis threshold of the at least one adjacent cell among the UEs handed over from the cell which is currently in service to the at least one among the adjacent cells.
This research was conducted as part of the Korea Communications Agency's “Development of combined control management systems for wired/wireless equipment based on OpenFlow.”